Gaya APA
Curtis, Helena. R.REF. (1983).
Biology / Helena Curtis (4th ed.).
:
Worth.
Gaya Chicago
Curtis, Helena. R.REF.
Biology / Helena Curtis.
4th ed.
:
Worth,
1983.
Text.
Gaya MLA
Curtis, Helena. R.REF.
Biology / Helena Curtis.
4th ed.
:
Worth,
1983.
Text.
Gaya Turabian
Curtis, Helena. R.REF.
Biology / Helena Curtis.
4th ed.
:
Worth,
1983.
Print.